1. Technical Field
The present invention relates to an apparatus for supplying power in a computer system, and more particularly to an apparatus which supplies power and which protects an auxiliary memory device and data stored in the auxiliary memory device, and a method therefor.
2. Related Art
Computer systems are information handling systems that are utilized by many individuals and businesses today. A computer system can be defined as a microcomputer that includes a central processing unit (CPU), a volatile memory, a non-volatile memory such as read only memory (ROM), a display monitor, a keyboard, a mouse or other input device such as a trackball, a floppy diskette drive, a compact disc-read only memory (CD-ROM) drive, a modem, a hard disk storage device, and a printer. A computer system's main board, which is a printed circuit board known as a motherboard, is used to electrically connect these components together. A computer system can be a desktop computer, a portable computer, or other type of computer.
The central processing unit is often described as a microprocessor. The microprocessor is an electronic component having internal logic circuitry handling most, if not all, the data processing in the computer system. The internal logic circuitry of microprocessors is typically divided into three functional parts known as the input/output (I/O) unit, the control unit, and the arithmetic-logic unit (ALU). These three functional parts interact together and determine the power and performance of the microprocessor. The combination of the control unit and the arithmetic-logic unit can be referred to as the central processing unit. Also, the combination of the input/output unit, the control unit, and the arithmetic-logic unit can be referred to as the central processing unit.
One example of non-volatile memory is read only memory. Information stored in non-volatile memory can remain unchanged even when there is a power failure. The information stored in non-volatile memory will stay there until it is changed. Read only memory is used to store important information such as instructions for the central processing unit. There are different types of read only memory including electrically-erasable-programmable-read-only-memory (EEPROM) chip and flash-read-only-memory (flash-ROM). The flash-ROM can also be referred to as flash memory.
Computer systems include a basic input output system (BIOS) which is an especially important program stored in read only memory. The basic input output system tests a computer every time the computer is powered on. The basic input output system can allocate a computer system's resources automatically, making adjustments needed to accommodate new hardware. Also, the basic input output system governs how system board components interact.
When the computer system is powered on, the basic input output system immediately takes control of the computer system and its components. The first duty of the basic input output system is to perform a series of diagnostic routines called the power on self test (POST) routine, which ensures that every part of the computer system's hardware is functioning properly.
I have found that an impediment frequently generated in the computer system is that data stored on the hard disk drive cannot be read due to damage to the hard disk drive. Such an impediment can be generated when power is cut off to the hard disk drive by a user turning off the power switch during operation of the hard disk drive. That is, since the head of the hard disk drive is close to the surface of a hard disk to access data stored on the hard disk, during operation of the hard disk drive, if power is cut off to the hard disk drive, the surface of the hard disk may become damaged. When damage occurs as described above, a damaged portion of the hard disk usually cannot be recovered, and information stored on the damaged portion is lost permanently. Such a problem is not limited to only the hard disk drive, and may also apply to an auxiliary memory device such as a floppy disk drive, a tape drive, and other connected components.
I have found that a hard disk drive can be damaged when power is cut off during operation of the hard disk drive. Efforts have been made to reduce this type of damage.
Exemplars of recent efforts in the art include U.S. Pat. No. 5,799,141 for REAL-TIME DATA PROTECTION SYSTEM AND METHOD issued to Galipeau, et al. U.S. Pat. No. 5,596,708 for METHOD AND APPARATUS FOR THE PROTECTION OF WRITE DATA IN A DISK ARRAY issued to Weber, U.S. Pat. No. 5,625,819 for METHOD AND APPARATUS FOR PERFORMING HEAP MANAGEMENT AND PROTECTING DATA STRUCTURE INTEGRITY IN NON-VOLATILE MEMORY issued to Hoffer, Jr., U.S. Pat. No. 5,598,567 for APPARATUS FOR CONTROLLING POWER SUPPLY IN A COMPUTER SYSTEM BY INTRODUCING DELAYS BEFORE ACTIVATION AND DEACTIVATION OF POWER issued to Ninomiya, U.S. Pat. No. 5,596,762 for SMALL-SIZE COMPUTER HAVING PLUGGABLE MEMORY UNIT FOR DATA PROTECTION issued to Rudi, and U.S. Pat. No. 5,193,176 for COMPUTER WORK SAVING DURING POWER INTERRUPTION issued to Brandin.
While these recent efforts provide advantages, I note that they fail to adequately provide a method for efficiently and conveniently avoiding damage to a hard disk drive when power is cut off during operation of the hard disk drive.